Removed packet prealloc API from the rest of the sources.

src/knot/ctl/knotc_main.c

src/knot/ctl/remote.c

src/knot/server/notify.c

src/knot/server/tcp-handler.c

src/knot/server/udp-handler.c

src/knot/server/xfr-handler.c

src/knot/server/zones.c

src/libknot/nameserver/name-server.c

src/libknot/packet/response.c

src/libknot/updates/xfr-in.c

src/utils/common/exec.c

src/utils/common/exec.h

src/utils/dig/dig_exec.c

src/utils/nsupdate/nsupdate_exec.c